Our goal is to understand the regulation of gene expression and to elucidate structure-function relationships in the genomes of higher eukaryotes. We will work with human globin gene clusters in attempts to learn the molecular basis for some of the many types of thalassemias in which a change in structure has resulted in an obvious change in function. We will compare the globin gene clusters of a series of different primates in order to learn what aspects of the complicated repeat structure of this cluster are functionally important. We will also study chicken globin genes because avian systems offer some advantages over mammalian cells (e.g., circulating nucleated erythrocytes, the possibility of a "stress globin"). We will rely heavily upon recombinant DNA techniques, restriction mapping and nucleotide sequence analysis in these studies. Special attention will be given to the further development of our computer program for determining RNA secondary structure. Here the emphasis will be on testing results against data from other methods (nuclease sensitivity, glyoxylation and crosslinking studies) and in using this data to help predict the structure. In a related project we will construct cloned gene pools doe isolated single human chromosomes.